import?java.awt.*;
import?javax.swing.*;
import?java.awt.event.*;
import?java.io.BufferedReader;
import?java.io.File;
import?java.io.FileOutputStream;
import?java.io.FileReader;
import?java.io.IOException;
import?java.io.InputStream;
import?java.io.FileInputStream;
import?java.io.FileNotFoundException;
import?java.io.PrintStream;
import?java.util.Date;
import?java.util.Random;
class?NoNameOfUser?extends?Exception
{
	public?NoNameOfUser（String?msg）
	{
		super（msg）;
	}
}
class?TypeDefault?extends?Exception
{
	public?TypeDefault（String?msg）
	{
		super（msg）;
	}
}
class?Operation
{
	protected?String?operation;
	protected?int?numberOfDigit;
	protected?int?operand1operand2userAnswer1rightAnswer1userAnswer2rightAnswer2;
	JLabel?jlblQuestion;
	JTextField?jtfUs